fix: freq coords need to take into account x-coords spacing

2017-01-18 09:02:53 +08:00 · 2017-01-18 09:02:53 +08:00 · 0a8d5b253a
commit 0a8d5b253a
parent 12f6bf916f
1 changed files with 4 additions and 2 deletions
--- a/pyqtgraph/graphicsItems/PlotDataItem.py
+++ b/pyqtgraph/graphicsItems/PlotDataItem.py
@ -679,8 +679,10 @@ class PlotDataItem(GraphicsObject):
            x2 = np.linspace(x[0], x[-1], len(x))
            y = np.interp(x2, x, y)
            x = x2
-        f = np.fft.rfft(y) / y.size
-        x = np.fft.rfftfreq(y.size)
+        n = y.size
+        f = np.fft.rfft(y) / n
+        d = (x[-1] - x[0]) / (n - 1)
+        x = np.fft.rfftfreq(n, d)
        y = np.abs(f)
        return x, y